1. Field of the Invention
The present invention relates to an optical fiber lighting apparatus.
2. Description of the Related Art
There has been proposed an optical fiber lighting apparatus that has LEDs arranged at the proximal end portion of an endoscope and guides light to the light-emitting unit at the distal end of the endoscope via an insertion portion by using a fiber bundle. The fiber bundle is a single bundle on the endoscope distal end side but is separated into three parts on the light source side, which are respectively and directly connected to the LEDs that emit red light, green light, and blue light.
This optical fiber lighting apparatus guides illumination light from the endoscope proximal end portion to the endoscope distal end portion by the fiber bundle, and uses only lenses at a light incident portion that causes light emitted from the LEDs to strike the separated incident ends of the fiber bundle. Accordingly, light that is emitted from the LEDs and does not strike the lenses are not used. The light guide efficiency of the system is poor, and sufficiently bright illumination light is hard to obtain.